1-(3 - aminopyrazinoyl) - 3 - substituted-3-thioisosemicarbazides and method for preparation

ABSTRACT

1-(3-AMINOPYRAZINOYL)-3-SUBSTITUTED-3-THIOISOSEMICARBAZIDES ARE DESCRIBED THAT CAN BE OPTIONALLY SUBSTITUTED IN THE 5- AND/OR 6-POSITION OF THE PYRAZINOYL MOIETY AND ADDITIONALLY OPTIONALLY SUBSTITUTED ON THE TERMINAL NITROGEN OF THE SMICARBAZIDE MOIETY. THESE COMPOUNDS ARE PREPARED EITHER BY ALKYLATION OF THE 1-(3-AMINOPYRAZINOYL)THIOSEMICARBAZIDE OR BY THE REACTION OF A 3-SUBSTITUTED-3-THIOSOSEMICARBAZIDE AND A 3-(3-AMINOPYRAZINOYLOXY)-ACRYLAMIDE WHICH IN TURN IS PREPARED BY REACTION BETWEEN A PYRAZINOIC ACID AND AN ISOXAZOLIUM SALT. THE PRODUCTS POSSESS SALURETIC AND DIURETIC PROPERTIES AND THEREFORE ARE USEFUL IN THE TREATMENT OF CONDITIONS ASSOCIATED WITH ABNORMAL RETENTION OF FLUID AND/OR SODIUM AND CHLORIDE IONS SUCH AS THE TREATMENT OR MANAGEMENT OF EDEMATOUS CONDITIONS.

United States Patent 01 ice Edward J. Cragoe, Jr., Lansdale, and Kenneth L. Shepard,

Ambler, Pa., assignors to Merck & Co., Inc., Rahway, NJ., a corporation of New Jersey No Drawing. Filed Nov. 13, 1968, Ser. No. 775,542 Int. Cl. C07d 51/76 US. Cl. 260-250 10 Claims ABSTRACT OF THE DISCLOSURE 1 (3 aminopyrazinoyl) 3 substituted 3 thioisosemicarbazides are described that can be optionally substituted in the and/ or 6-position of the pyrazinoyl moiety and additionally optionally substituted on the terminal nitrogen of the semicarbazide moiety. These compounds are prepared either by alkylation of the 1-(3-aminopyrazinoyl)thiosemicarbazide or by the reaction of a 3-substituted- 3 -thioisosemicarbazide and a 3-(3-arninopyrazinoyloXy)-acrylamide which in turn is prepared by reaction between a pyrazinoic acid and an isoxazolium salt. The products possess saluretic and diuretic properties and therefore are useful in the treatment of conditions associated with abnormal retention of fluid and/or sodium and chloride ions such as the treatment or management of edematous conditions.

and includes the pharmacologically acceptable salts thereof wherein X is selected from hydrogen and amino of the structure NR R wherein NR R represents an unsubstituted or a substituted amino group wherein R is selected from (1) hydrogen,

(2) alkyl, preferably lower alkyl or from 1 to about 6 carbon atoms either straight or branched chain and either saturated or unsaturated, e.g., methyl, ethyl, propyl, isopropyl, allyl, propenyl, butyl, isobutyl, secondary butyl, pentyl, isopentyl neopentyl, hexyl and the like,

R is selected from (1) hydrogen,

(2) alkenyl, preferably lower alkenyl of from 3 to about 5 carbon atoms, e.g., allyl, propenyl or the like,

(3) alkynyl, preferably lower alkynyl of from 3 to 5 carbon atoms, e.g., propargyl and the like,

(4) lower cycloalkyl of from 3 to about 7 carbon atoms, e.g., cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl and the like,

3,555,023 Patented Jan. 12, 1971 (5) mononuclear aryl, especially phenyl, either unsubstituted or substituted, such as with halo, e.g., chloro, bromo, or fluoro, lower alkyl of from 1 to about 3 carbon atoms, e.g., methyl, ethyl, and propyl, or lower alkoxy, e.g., methoxy, ethoxy, propoxy, and the like,

(6) lower alkoxy, preferably lower alkoxy of from 1 to 4 carbon atoms, e.g., methoxy, ethoxy, isopropoxy and the like,

(7) substituted amino selected from pyridylamino and pentamethyleneamino,

(8) alkyl, preferably lower alkyl of from 1 to about 6 carbon atoms either straight or branched chain such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary butyl, pentyl, isopentyl, neopentyl, hexyl and the like, either unsubstituted or substituted with one or more substituents selected from (a) lower alkoxy of from 1 to about 3 carbon atoms, e.g., methoxy, ethoxy, propoxy and the like,

(b) lower cycloalkyl of from 3 to about 6 carbon atoms, e.g., cyclopropyl, cyclopentyl, cyclohexyl and the like,

(c) heterocyclic group of 5 or 6 nuclear members and containing one or more hetero atoms selected from oxygen and nitrogen, especially furyl and pyridyl,

(d) mononuclear aryl, especially phenyl, either unsubstituted or substituted with such as halo, e.g., chloro, bromo, or fiuoro, lower alkyl of from 1 to about 3 carbon atoms, e.g., methyl, ethyl, or propyl, or lower alkoxy of from 1 to about 3 carbon atoms, e.g., methoxy ethoxy, propoxy and the like,

(e) NR' R wherein R is selected from (1) alkyl, preferably lower alkyl of from 1 to about 5 carbon atoms, e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, pentyl, isopentyl, neopentyl and the like,

(2) lower alkylcarbonyl, of from 2 to about 3 carbons, e.g., acetyl, propionyl, and the like,

R is alkyl, preferably lower alkyl of from 1 to about 5 carbon atoms, e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, pentyl, isopentyl, neopentyl, and the like, R and R when lower alkyl can be linked together either directly or through a hetero atom such as nitrogen or oxygen to form a heterocyclic ring with the nitrogen to which they are attached, e.g,, piperidino, pyrrolidinyl, morpholino, piperazinyl, N-lower alkyl piperazinyl, and the like;

R and R when lower alkyl can be linked together either directly or through a hetero atom such as nitrogen or oxygen to form a heterocyclic ring with the nitrogen atom to which they are attached forming, e.g., piperidino, pyrrolidinyl, morpholino, piperazinyl, N-lower alkylpiperazinyl, and the like;

Y is hydrogen, halogen, preferably chloro, bromo or iodo,

phenyl, lower alkyl;

R is selected from lower alkyl and phenyl-lower alkyl, lower alkyl-phenyl-lower alkyl, halophenyl-lower alkyl, especially chloroand bromophenyl-lower alkyl; and

R is selected from hydrogen, lower alkyl, lower alkenyl, phenyl, halo (chloro or bromo)-phenyl, and monoor di-phenyl-lower alkyl (C In the foregoing definitions unless otherwise noted, the

lower alkyl radicals advantageously have from 1 to 5 carbon atoms and are either straight or branched chain,

the lower alkenyl radicals have from 3 to 5 carbon atoms and the cycloalkyl radicals have from 3 to 6 nuclear carbons and are selected from cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

The products of this invention are prepared either by alkylation of the desired 1-(3-aminopyrazinoyl)-thiosemicarbazide or by reacting a 3-substituted-3-thioisosemicarbazide with a very reactive 3-(3-aminopyrazinoyloxy) acrylamide which itself is prepared by reaction between a pyrazinoic acid and an isoxazolium salt.

The preparation of the compounds by the alkylation of the 1-(3-aminopyrazinoyl)-thiosemicarbazide can be illustrated by the following reaction scheme:

(II) (III) P( INTI:

Y \N/ coNnML N X N112 I s Y- o ONIINI'ICNII n This reaction preferably is carried out in the presence of a solvent and with heating from about steam bath temperature up to the reflux temperature of the reaction mixture. The reactants can be employed in equimolecular quantity although an excess of one or the other can be employed, usually an excess of the isothiocyanate, V. Solvents such as lower alkanols, acetonitrile, acetic acid, dilute hydrochloric acid or pyridine can be employed for the reaction medium although other usual solvents can be used as well.

Although many of the pyrazinoic acid hydrazides, IV, are known compounds, those that are not known can be prepared by known methods including reaction of an alkyl pyrazinoate and hydrazine.

The intermediate esters generally are prepared by one of the processes shown below. Many esters, however, previously have been described, some of which were made by methods other than those illustrated below which methods would also be useful in preparing other desired ester starting materials.

N N 7 k NII Anion L- NIIg i l Y COOII Y COOAlk wherein X, Y, R and R have the meaning assigned above, R represents lower alkyl having from 1 to about 3 carbon atoms or unsubstituted or substituted phenyl, wherein the substituent is a lower alkyl having 1 to 3 carbons or a sulfonate (SO R represents hydrogen or a hydrocarbon radical which when linked to R forms with the carbon atoms to which R and R are joined an ortho-phenylene group; and R represents lower alkyl (C The above reaction is carried out by mixing the acrylamide, VI, with the 3 substituted-3-thioisosemicarbazide, VII, in either equimolecular proportions or if desired the thioisosemicarbazide can be employed in excess. As reaction medium a lower alkanol, preferably isopropanol or tertiary butanol, is employed although other solvents such as dimethylformamide, dioxane, dichloromethane, tetrahydrofuran, acetonitrile and the like can be used. The reaction can be carried out at room temperature although it is facilitated with heating up to about reflux temperatures.

The acrylamide, VI, can be prepared from a 3-aminopyrazinoic acid and an isoxazolium salt according to the following reaction scheme:

The X, Y and Rs in the above structures have the meanings assigned above. Z is a salt forming anion, and advantageously can be the perchlorate or 2,4-dinitrophenylsulfonate. Approximately equivalent amounts of the pyra zinoic acid, X, an isoxazolium salt, XII, and a tertiary amine are dissolved in a solvent and stirred to form the acrylamide, VI.

Generally the pyrazinoic acid and tertiary amine, such as a tri(loweralkyl)amine, e.g., trimethylamine, triethylamine, tripropylamine or the like are dissolved in a solvent such as dimethylformamide, dimethyl sulfoxide and dimethyl sulfone, acetonitrile or tetrahydrofuran, and stirred for a period of from a few minutes to several hours. The isoxazolium salt then is added and the mixture stirred from about 1 to about 4 hours, usually about 2 hours at ambient temperature, although gentle heating up to about 50 C. can be employed. The acylamide, VI, usually is sufficiently stable to be isolated and purified, and often is isolated simply by diluting the reaction mixture with water which precipitates the 3-(3-aminopyrazinoyloxy)acrylamide. Alternatively, the acrylamide, VI, can be obtained by evaporation of the reaction mixture.

The intermediate pyrazinoic acids, X, generally are prepared by the hydrolysis of the corresponding alkyl esters, XI. The hydrolysis usually is carried out using a solution of aqueous base, such as, sodium hydroxide or potassium hydroxide and a solvent such as, isopropyl alcohol, ethanol and the like, and refluxing the mixture for one to 10 hours. The pyrazinoic acid then is isolated by cooling and acidifying the mixture with an acid, such as hydrochloric acid, sulfuric acid and the like If desired, salts of the novel products, I, of this invention can be prepared by conventional methods such as dissolving product I in alcohol and adding the desired acid.

The products of this invention can be administered to man or animals in the form of pills, tablets, capsules, elixirs, injectable preparations and the like and can comprise one or more of the compounds of this invention as the only essential active ingredient of the pharmaceutical formulation, or the novel product( s) can be combined in pharmaceutical formulations with other diuretic agents or indeed other therapeutic agents. The products of this invention advantageously are administered at a dosage range of from about mgs. per day to about 750 m gs. per day or at a somewhat higher or lower dosage at the physicians discretion, preferably in subdivided amounts on a 2 to 4 times a day regimen. These formulations can be prepared by the usual methods for making unit dosage forms of compounds for oral or parenteral administration.

In the following text illustrative methods for making intermediates and their use in preparing the novel products of this invention are detailed in the following order:

THIOSEMICARBAZIDE METHOD (A) Preparation of the alkyl 3-amino-5-X-6-Y-pyrazinoates,

(B) Preparation of the hydrazides from the pyrazinoates (C) Preparation of the pyrazinoylthiosemicarbazides from the hydrazides of (B),

(D) Examples illustrative of the preparation of the novel pyrazinoylthioisosemicarbazides of this invention from said pyrazinoylthiosemicarbazides.

ACRYLAMIDE METHOD (E) Preparation of pyrazinoic acids from the esters of (A) or other known esters,

(F) Preparation of the pyrazinoylacrylamides from the pyrazinoic acids of (E) and an isoxazolium salt,

(G) Examples illustrating the preparation of the novel pyrazinoylthioisosemicarbazides of this invention from said pyrazinoylacrylamides.

(A) Preparation of alkyl 3-amino-5-X-6- Y-pyrazinoates (A-1) Methyl 3-amino-5-dimethylamino-6-chloropyrazinoate.A suspension of methyl 3-amino-5,6-dichloropyrazinoate (178 g., 0.8 mole) in 2-propanol (1.1 liters) is stirred While dimethylamine (200 g., 4.44 moles) in 2-propanol (2 liters) is added, and then the mixture is refluxed for an hour. The product that separates is removed by filtration and dried. The yield is 177.2 g. (97%). After recrystallization from methanol the methyl 3-amino-5-dimethyl-amino-6-chloropyrazinoate melts at 145.5-1465" C.

Analysis.-Calculated for C H ClN O (percent): C, 41.66; H, 4.81; N, 24.29. Found (percent): C, 41.73; H, 4.52; N, 24.24.

(A-2) Preparation of methyl 3-amino-5-(2,2-pentamethylenehydrazino)-6-chloropyrazinoate.-A mixture of methyl 3-amino-5,6-dichloropyrazinoate (22.2 g., 0.1 mole), N-aminopiperidine (10.0 g., 0.1 mole), triethylamine (15 ml.), and dimethyl sulfoxide ml.) is warmed on the steam bath with stirring for three hours. The solution is diluted with water (350 ml.) and the solid that separates is collected and dried yielding 25.6 g. of methyl 3-amino-5-(2,Z-pentamethylenehydrazino)- 6-chloropyrazinoate, M.P. 195202 C. Recrystallization from acetonitrile or butyl chloride gives material with M.P. 207-209 C.

Analysis.Calculated for C H ClN O (percent): C, 46.24; H, 5.65; N, 24.51. Found (percent): C, 46.39; H, 5.63; N, 24.73.

(A-3) Preparation of methyl 3-amino-5-[2-(2-pyridyl)hydrazino] 6 chloropyrazinoate.A mixture of methyl 3-amino-5,6-dichloropyrazinoate (22.2 g., 0.10 mole), 2-hydrazinopyridine (11.0 g., 0.10 mole), triethylamine (22 ml.), and dimethyl sulfoxide 100 ml.) is heated on the steam bath for three and one-half hours. The reaction mixture is diluted with water (250 ml.) and the solid that forms is collected and dried, yielding 29.8 g. of methyl 3-amino-5-[2-(2-pyridyl)hydrazino] 6-chlopyrazinoate M.P. 201-205 C. Recrystallization from acetonitrile gives material with M.P. 203206 C.

Analysis.Caleulated for C H ClN 0 (percent): C, 44.83; H, 3.76; N, 28.52. Found (percent): C, 44.88; H, 3.79; N, 28.82.

By employing substantially the same method described in (A-l), above, but substituting. for the dimethylamine, equimolar quantities of the amines identified in Table I there is obtained the corresponding methyl 3-amino-5- substituted-amino-6-chloropyrazinoate products identified in Table I according to Equation A.

TABLE I.-EQ,UATION A Rs N R5 N 01 NH2 N 4 NH2 6 Cl -COOCH3 RB 01 COOCH3 Product Analysis Calculated Found M.P., R R C. Formula C H N C H N Preparation:

A-4 CHECCH2 H 168-169 O9H9C1N402 44.92 3.77 23.28 44.82 3.73 23.09 A5 OHaOCH2CHg H 142-144 OQHlzNlOaCl 41.47 5.03 21.49 41.56 5.03 21.38

A-G II -191 CrzHuClNaOz 40.07 4.12 23.85 40.39 4.06 23.88

TABLE I-Continued Product Analysis Calculated Found M.P., R R 0. Formula C H N C H N Preparation:

A-7 CH H 170-171 C121112N5O 2C1 10. 07 1.12 23. 85 40. 36 4.18 23. G1

A-B CHaC NH(CH2) z- 11 208-210 CmHuNaO C1 11. 75 1. 00 24. 34 42. 04 4. 85 21. 60

('3 0 CH3 CHa-N-(CH2)2 H 175-179 C11HmClN O A-lO 01-130 ONH(OH2) 3- 11 180-182 CnHmN5O Cl A-ll (C2115) zNCHzCHg- H 114-116 C12H2oN50 Cl A12 (C2115) zN(CH2)2'- CH3- 51-51 C13HzzClN50z A-13 (CH N(CHg) 11 108-109 C H N OzCl A1-1 (CH3)2N(CHz)4 1:1 170-171 C1zH2uClN5OzHCl A-15 N(CH2)z- H 121-122 C12Hl8N5O 2C1 -18. 08 6. 05 23. 37 48. 31 6. 40 23. 76

A-l6 CHEN N(Cl12)a- 11 148-149 CrlHzaNsOzCl 11). 05 6. 76 24. 52 48. 05 6. 64 24.

A-17 O 1 I(CH' 11 158-160 C13I'I10N50 C1 17. 34 6.11 21. 24 47. 41 6. 04 21.17

A-lS CH3(C1I2)2- C11 83-85 Cl011\5N4Cl02 1G. 12 5. 84 21. 66 46. 5. 21. 70 A-l.) (CH3) 2N (CH2) 3 CH3- 202-203 CIE1'IZQCIN502(I1 Cl) 42. 61 6. 26 20. 71 42. 51 0. 0E) 21. 02

A-20 CH2CIIgNCHzCHz- 143-145 C121'I1BN502C1 18. 08 G. 05 23. 36 47. 97 G. 11 23. 19 A-ll -CH' 'CHzOC1'12CH2 197-198 C1ol113N4O Cl -11. 04: *1. 20. 55 44. 32 4. 74 20. 07

C H3\ A-22 N(CH2) 2- 11 157-158 CnHzoClNsOa (1113101110) 47. 28 6. 07 16. 22 47. 43 6. 06 16. 52

l'l-c Hg The following compounds also are prepared by the 6-chloropyrazinoate (2.86 g., 0.01 mole), hydrazine method described in (A-l), above, by replacing the dimethylamine with an equimolecular quantity of (A23 2- (N-acetyl-N-ethylamino ethylamine (A-24) 2-piperidinoethylamine (A-25) 3-piperidinopropylamine thereby forming:

(A-23) Methyl 3-amino-5-[2-(N-acetyl-N-ethylamino) ethylamino]-6-chloropyrazinoate (A-24) Methyl 3-amino-5-(piperidinoethylamino)-6- chloropyrazinoate and (A-25) Methyl 3-amino-5-(3-piperidinopropylamino)- 6-chloropyrazinoate (B) Preparation of 3-amino-5-X-6-Y-pyrazinoic acid hydrazides (B-l) 3-amino-5-diethylamino-6-chloropyrazinoic acid hydrazide. Hydrazine (20 ml. of 64% aqueous solution) is added to a solution of methyl 3-amin0-5-diethylamino-6-chloropyrazinoate (10.0 g., 0.04 mole) in ethanol (250 ml.) and the reaction mixture is refluxed for 4 hours. The solvent is then removed in vacuo and the residue washed out with water and dried to yield 9.0 g. (87%) of 3-amino-5-diethylamino-6-chloropyrazinoic acid hydrazide melting at 137140 C. After crystallization from 2-propano1 the compound melts at 142-145 C.

Analy'sis.-Calculated for C H N ClO (percent): C, 41.79; H, 5.84; N, 32.49. Found (percent): C, 42.00; H, 6.05; N, 32.10.

(13-2) Preparation of 3-amino-5-(2,2-pentamethylenehydrazino)-6-chlor0pyrazinoic acid hydrazide. A mixture of methyl 3-amino-5-(2,Z-pentamethylenehydrazino)- 0.68 g.), dimethylformamide (5 ml.), and ethanol (30 ml.) is heated in the steam bath with stirring for 5 hours then cooled to room temperature. The white solid is collected, washed with a little ethanol, and dried to yield 1.97 g. of 3-amino-5-(2,2-pentamethylenehydrazino)-6-chloropyrazinoic acid hydrazide, M.P. 218221 C. Recrystallization from ethanol gives material melting at 221-222 C.

Analysis.Calculated for C H ClN O (percent): C, 42.03; H, 5.64; N, 34.32. Found (percent): C, 42.01; H, 5.71; N, 34.38.

(B-3) Preparation of 3-amino-5-[2-(2-pyridyl)hydrazino]-6-chloropyrazinoic acid hydrazide.A mixture of methyl-3-amino-5-[2-(2-pyridyl)hydrazino] 6 chl0r0- pyrazinoate (11.75 g., 0.04 mole), hydrazine (64% in water, 50 ml.), and ethanol (175 ml.) is heated to reflux for four hours. The mixture is diluted with water ml.) and the solid collected and dried at 70 C., yielding 11.52 g. of 3-amino-5-[2-(Z-pyridyl)hydrazino]-6-chloropyrazinoic acid hydrazide, M.P. 229232 C. (dec.). Recrystallization from 50% aqueous dimethylformamide gives material with M.P. 230233 C. (dec.).

Analysis.Calculated for C H ClN O (percent): C, 40.75; H, 3.76; N, 38.03. Found (percent): C, 40.90; H, 3.73; N, 38.34.

By employing substantially the method described in (B-l), above, but substituting for methyl 3-amino-5-diethylamino-6-chloropyrazinoate equimolar quantities of the methyl pyrazinoates identified in Table II there is produced the corresponding pyrazinoic acid hydrazides, also identified in Table II for each of which physical constants are provided under End Products, according to Equation B.

TABLE IICntinued End Product Analysis Ester Calculated Found from M.P., Preparation PrepnJ X Y C. Formula C H N C H N 13-31 A-l (CH zN- Cl 193-5 C7H11C1N50 3G. 45 4. 81 36. 44 36. 51 5. 01 36. 84

0& 13-32 /N 153-4 CnHmNaO 57. 34 5. 92 30.86 57. 77 5. 81 30. 71

C H; C33 18-33 I Cl 13-46 CslinNeCio 30. 27 5. 3G 34. 35 39. 3G 5. 51 34. 39

02111.5 CE; 13-34 A-IS. /N C1 133-6 CpHmClNsO 41. 78 5. 84 32. 49 41. 92 5. 84 32. 31

13-35 A-ZZ N(CH2) 2NH- Cl 88 C12H22C1N70 45. G3 7. 02 31. 45. 72 G. 73 31. 43

n-C4H9 13-36 N Cl 181-2 Cvl'IlaClNeO 42. 11 5. 1O 32. 74 42. 45 5. 0G 32. 86

13-37 CH3-N N- Cl 189-90 CH15C1N7O 27. 69 3. 71 28.11 3. 62

13-38 A- C2H5N N-- C 168-70 C|1H1 C1N O -14. 07 6. 05 44. 20 5. 66

13-39 A-Zl O N- C! 90-92 CnH1 C1N 602 39. 64 4.80 30. 82 39. 43 4. 57 30. 64

Ester Ester from from Preparation Prepn. X Y Preparation Prcpn. X Y

13-40 HgN- Br 13-49 Cl -C H2C IIzNH- 13-41 II2N I 13-50 O Cl To 112N11- il 13-42 Cl B-slnu-u-nn 11-23 CzH N(CHz)zNII- Cl O C H B43 A-4 CHECCHQNH- Cl B-52 A-24 N-(CH2) 2NH- Cl C H2NII Cl -(CII2)3NII- 01 B CII3(CII;O)N CI B 54 C1 -NI[:- Cl

BAG CF CII2NII Cl B- CH N DH;

B47 C F CH:CII2NH CI 13-56 C13;

N-- Cl C H9: 0 I'I-C Hg B-57 C H 3 13-48 CH CHzNH- C1 I I C] n-CAI'IQ l Ester known unless otherwise noted.

(C) Preparation of 1-(3-amino-5-X-6-Y-pyrazinoyl)- I thiosemicarbazides (C-l) Preparation of 1-(3,S-diamino-6-chloropyrazinoyl)thiosemicarbaz ide.-A mixture of 3,5-diamino-6- chloropyrazinoic acid hydrazide, from preparation (B-4), (6.06 g.; 0.03 mole) and potassium thiocyanate (3.3 g.; 0.034 mole) in glacial acetic acid (120 ml.) is heated on the steam bath for two hours. The. reaction mixture is cooled to room temperature and the solid removed by filtration. The solid material is dissolved on hot dimethylformamide (20 ml.) and reprecipitated by addition of water to give 2.19 g. of 1-(3,5-diamin-6-chloropyrazinoyl)thiosemicarbazide, M.P. 241.5-243 C. (dec.). After recrystallization from a mixture'of dimethylformamide and water, the material melts at 242.5-244 C. (dec.).

AnaIysis.-Calcu1ated for C H ClN' OS (percent): C, 27.53; H, 3.08; N, 37.47. Found (percent): C, 27.74; H, 2.8-8; N, 37.61.

(C-2) Preparation of 1[3-amino-5-(Z-dimethylarninoethylamino)-6 chloropyrazinoyl]thiosemicarbazide.3- amino 5-(2-dimethylaminoethylamino)-6-chloropyrazinoic acid hydrazide (10.92 g.; 0.04 mole), from prep aration (13-22), and potassium thiocyanate (7.76 g.; 0.08 mole), are mixed with N hydrochloric acid (75 ml.) and refluxed for 3 hours. The solution is cooled and allowed to stand overnight. Water (100 ml.) is added and the solid present is collected by filtration. The yellow solid obtained is dissolved in hot water (200 ml.) treated with decolorizing charcoal, filtered and the filtrate Inade alkaline by addition of 6 N ammonium hydroxide (10 ml.). The yellow solid that precipitatesis collected and dried to give 7.38 g. of 1-[3-amino-5-(Z-dimethylaminoethylamino -6-chloropyrazinoyl] thiosemicarb azide, M.P. 201 C. Recrystallization from nitromethane gives material melting at 202-203" C. (dec.). &

Analysis.Calculated for C H ClN Os (percent): C, 36.08; H, 5.08; N, 33.99. Found (percent): C, 36.43; H, 5.0 N, 33.23.

(C-3) Preparation of 1-(3.5-diamino-6-chloropyrazinoyl)-4-allylthiosemicarbazide.-3,5 diamino-6-chloropyrazinoic acid hydrazide (6.0 g.; 0.03 mol), from Preparation (B-4), and allyl isothiocyanate (4.95 g.; 0.05 mole) are mixed with glacial acetic acid (120 ml.) and warmed on the steam bath for two hours. The reaction mixture is diluted with water (250 ml.) and chilled in an ice bath. The solid that separates is collected by filtration and dried to give 7.1-0 g. (79%) of 1-(3,5-diamino-6-chloropyrazinoyl) 4-allylthiosemicarbazide, M.P. 210-212" C. (dec.). Recrystallization from acetonitrile gives material melting a't 2l3215 C. (dec.).

Analysis-Calculated for C HmClNqOS (percent): C, 35.82; H, 4.01; N, 32.49. Found (percent): C, 35.86; H, 4.35; N, 32.46.

(C-4) Preparation of 1-(3-amino-6-chloropyrazinoyl) 4-allylthiosemicarbazide.-A refluxing. solution of 3- amino-6-chlorpyrazinoic acid hydrazide (21.41 g.; 0.15 mole) in 2-methoxy-ethanol (225 ml.) is treated with allyl isothiocyanate (17.85 g.; 0.18 mole) and refluxing is continued for two hours. The reaction mixture then is concentrated to a paste under reduced pressure and the residue is triturated with ethanol to give 26.28 g. (61%) of 1-(3-amino-6-chloropyrazinoyl)-4:allylthiosemicarbazide, M.P. 203-205 C. Recrystallization from acetic acid gives the product in the form of orange prisms, M.P. 208-209 C.

Analysis. Calculated for C H ClN OS (percent): C, 37.70; H, 3.87; N, 29.31. Found (percent): C, 38.02; H, 3.80; N, 29.37.

(C-) Preparation of 1-(3-amino-6-chloropyrazin0yl)- thiosemicarbazide.A solution of 3-amino-6-ch1oropyrazinoic acid hydrazide (3.8 g.; 0.02 mole) and potassium 14 thiocyanate (2.4 g.; 0.024 mole) in acetic acid (40 ml.) is heated one hour on the steam bath. The crystalline product that separates is collected on a filter and recrystallized from a mixture of isopropyl alcohol and water to give 1.7 g. (68%) of 1-(3-amino-6-chloropyrazinoyl)thiosemicarbazide, M.P. 236-237 C. (dec.).

Analysis-Calculated for C H ClN OS (percent): C, 29.21; H, 2.86; N, 34.07. Found (percent): C, 29.55; H, 3.03; N, 34.30.

(C-6) Preparation of 1-(3.5-diamino-6-chloropyrazinoyl)-4-phenylthiosemicarbazide.A mixture of 3,5-diamino-6-chloropyrazinoic acid hydrazide (6.06 g.; 0.03 mole), from Preparation (B-5), and phenyl isothiocyanate (6.0 ml.) in glacial acetic acid (120 ml.) is heated on the steam bath for one hour, cooled and diluted slowly with water (250 ml.) and set aside overnight. The solid that forms is collected and dried to give 6.4 g. (63%) of 1-(3,5-diamino-6-chloropyrazinoyl) 4 phenylthiosemicarbazide, M.P., depending upon the rate of heating, 206-208" C. (fast heating); 223224 C. (slow heating), both with decomposition. Recrystallization from aqueous isopropyl alcohol gives material melting at 207208 C. (fast heating); 224-226 C. (slow heating), both with decomposition.

Analysis.Calculated for C H ClN OS- (percent): C, 42.66; H, 3.58. Found (percent): C, 43.14; H, 3.64.

The above reaction when carried out in the presence of pyridine as a solvent gives material identical with that obtained in preparation (C-6).

(C-7) Preparation of 1-{3-amino-5-[2-(2-pyridyl)hydrazino]-6 chloropyrazinoyl}thiosemicarbazide.3- amino-S-[2-(2-pyridyl)hydrazino]-6 chloropyrazinoic acid hydrazide (3.4 g.; 0.0115 mole), from Preparation (B-3), and potassium thiocyanate (2.23 g.; 0.023 mole) are mixed with N hydrochloric acid ml.) and heated to reflux three hours. The resulting clear yellow solution is cooled and allowed to stand overnight. The solid that separates is collected and dried to give 1.70 g. (43%) of 1-{3-amino-5- [2- (2-pyridyl)hydrazino] -6-chloropyrazinoyl}thiosemicarbazide, M.P. 226-229 C. (dec.). Recrystallization from dimethyl-formamide by the addition of acetonitrile gives material melting at 228-231 C. (dec.).

Analysis."Calculated for C H ClN oS (percent): C, 37.34; H, 3.42; N, 35.65. Found (percent): C, 37.13; H, 3.35; N, 35.40.

(C-8) Preparation of 1-(3,5-diamino 6-chloropyra- Zinoyl)-4-methylthiosemicarbazide.-A mixture of 3,5- diamino-6-chloropyrazinoic acid hydrazide (6.06 g.; 0.03 mole), from preparation (B-4), and methyl isothiocyanate (3.67 g.; 0.05 mole) in glacial acetic acid (120 ml.) is heated on the steam bath for two hours. The reaction mixture is diluted with water (250 ml.) and the resulting solid is collected and dried to give 6.53 g. (79%) of 1- (3,5-diamino -6-chloropyrazinoyl) 4-methylthiosemicarbazide, M.P. 270-273 C. (dec.). Recrystallization from hot dimethylformamide gives material melting at 271-273 C. (dec.).

Analysis.-Calculated for C H ClN OS (percent): C, 30.49; H, 3.66; N, 35.56. Found (percent): C, 30.70; H, 3.91; N, 35.53.

The above reaction when carried out employing pyridine as the solvent gives the same product.

(C-9) Preparation of 1-[3-amino 5-(2,2-pentamethylenehydrazino) 6 chloropyrazinoyl]thiosemicarbazide.A solution of 3-arnino-5-(2,2-pentamethylenehydrazino)-6-chloropyrazinoic acid hydrazide (5.71 g.; 0.02 mole) from preparation (B-2), and potassium thiocyanate (3.88 g.; 0.04 mole) in N hydrochloric acid (40 ml.) is refluxed for two hours. The clear solution then is diluted with water (100 ml.) and neutralized by the addition of dilute ammonium hydroxide. The solid that separates is collected and dried to give 5.8 g. of 1- [3 amino-5 (2,Z-pentamethylenehydrazino) 6-chloropyrazinoyl]thiosemicarbazide, M.P. 230-233 C. (dec.).

15 Recrystallization from nitromethane with a little added dimethylformamide gives material melting at 239.5- 242.5 C. (dec.).

Analysis.Calculated for C H CIN OS (percent): C, 38.31; H, 4.97; N, 32.50. Found (percent): C, 38.67; H, 5.12; N, 32.55.

(C-lO) Preparation of l-{3 amino 5 [Z-(Z-pyridyl) hydrazino] 6-chloropyrazinoyl} 4-a1lyl 3-thiosemicarbazide.-3-amino 5-[2-(2 pyridyl)hydrazino] 6- chloropyrazinoic acid hydrazide (6.49 g.; 0.022 mole), from preparation (B-4), and allyl isothiocyanate (3.92 g.; 0.044 mole) are mixed with glacial acetic acid (130 ml.), and heated on a steam bath with stirring for two hours. The reaction mixture is diluted with Water (500 ml.). and neutralized with dilute aqueous ammonium hydroxide (150 ml.). The yellow solid that separates is 15 16 collected by filtration and dried, yielding 7.9 g. (91%) 0f 1-{3 amino-5 [2-(2 pyridyl)hydrazino] 6-chloropyrazinoyl}-4-allyl-3-thiosemicarbazide, M.P. 2l8222 C. Recrystallization from dimethylformamide gives material melting at 226-227 C. (dec.).

Analysis.-Calculated for C H CIN OS (percent): C, 42.69; H, 4.10; N, 32.01. Found (percent): C, 42.55; H, 4.07; N, 31.94.

Additional l-(3 amino-S-X-6-Y-pyrazinoyl)thiosemicarbazides prepared by substantially the same procedure described in preparation (C-l) are identified in Table III. The products are prepared by reacting the pyrazinoic acid hydrazide IV with the thiocyanate or isothiocyanate to give the desired product II wherein in each of the reactants and end product X, Y and R have the significance given in the table.

TABLE III-Cntinued Hydrazldo from Irepn. X Y R Preparation (Hi2 13-50 0 Cl CII;CH=C1I W HAIHZNII- C-03 13-51 CzH N(CHz)zNH Cl 'CI12CI{:CII2

C O C 11 0-64 13-5.! 01 CH2C11=CH N(CHz)zNlI- G-65 13-53 Cl CH2CH=CII2 1 Hydrazide known unless otherwise noted.

The following examples are illustrative of the methods for making the compounds of this invention from thiosemicarbazides and are not to be considered as limiting the invention to the particular procedural conditions employed or to the particular products prepared thereby.

EXAMPLE 1 1- 3,5 -diamino-6-chloropyrazinoyl) -3-methyl-3- thioisosemicarbazide A solution of 1-(3,5-diamino-6-chloropyrazinoyl)- thiosemicarbazide (6.0 g.; 0.023 mole), from preparation (C1), in 0.5 N sodium hydroxide solution (65 ml.) is stirred at room temperature while a solution of methyl iodide (4.5 ml.) in ethanol (5 ml.) is added rapidly. The mixture is stirred one-half hour and the precipitated solid is collected by filtration. Recrystallization of the solid material from 50% aqueous ethanol gives 3.68 g. of 1-(3,5-diamino-6-chloropyrazinoyl)-3-methyl 3 thioisosemicarbazide in the form of fluffy yellow needles, M.P. 320 C.

Analysis.-Calculated for C H ClN OS (percent): C, 30.49; H, 3.66; N, 35.56. Found (percent): C, 30.84; H, 3.65; N, 35.77.

EXAMPLE 2 1-[3-amino-5-(2-dimethylamin0ethylamino) 6 chloropyrazinoyl]-3-methyl-3-thioisosemicarbazide A solution of 1-[3-amino-5-(Z-dimethylaminoethylamino)-6-chloropyrazinoyl]thiosemicarbazide (4.15 g.; 0.0125 mole), from preparation (C-2), in 0.5 N sodium hydroxide solution (50 ml.) is stirred at room temperature while a solution of methyl iodide (1.77 g.; 0.0125 mole) in ethanol (5 ml.) is added. After /2 hour the aqueous solution is extracted with two 50 ml. portions and four ml. portions of ethyl acetate. The combined ethyl acetate fractions are dried over anhydrous magnesium sulfate and evaporated under reduced pressure. The residual yellow solid is recrystallized from ethyl acetate to give 0.50 g. of 1-[3-amino-5-(Z-dimethylaminoethylamino)-6-chloropyrazinoyl]-3-methyl 3 thioisosemicarbazide, M.P. 178-181 C. (dec.).

Analysis.--Calculated for C H ClN OS (percent): C, 38.09; H, 5.52; N, 32.31. Found (percent): C, 38.11; H, 5.38; N, 32.46.

EXAMPLE 3 1-( 3,5 -diamino-6-chloropyrazinoyl)-3-rnethyl-4- allyl-3-thioisosemicarbozide A solution of l-(3,5-diamino-6-chloropyrazinoyl)-4- allyl-3-thiosemicarbazide (6.02 g.; 0.02 mole), from preparation (C-3), in dilute sodium hydroxide (300 ml. of 0.5 N) is stirred at room temperature while a solution of methyl iodide (4 ml.) in ethanol (10 ml.) is added. The mixture is stirred for one hour and the solid that 1-(3-amino-6-chloropyrazinoyl)-3-ethyl-4-allyl-3- thioisosemicarbazide By replacing the thiosemicarbazide and the methyl iodide employed in Example 1 by equimolecular quantities of 1-(3-amino--chloropyrazinoyl)-4-allylthiosemicarbazide, from preparation (C-4), and ethyl bromide respectively, and following substantially the same procedure described in Example 1 there is obtained 1-(3-amino-6- chloropyrazinoyl -3-ethyl-4-allyl-3-thioisosemicarbazide.

EXAMPLE 5 1- 3-amino-6-chloropyrazinoyl) -3-isopropyl-3- thioisosemicarbazide By replacing the thiosemicarbazide and the methyl iodide employed in Example 1 by equimolecular quantities of 1-(3-amino-6-chloropyrazinoyl)thiosemicarbazide, from preparation (C-5), and isopropyl iodide respectively, and following substantially the same procedure described in Example 1, there is obtained 1-(3-amino-6- chloropyrazinoyl)-3-isopropyl-3-thioisosemicarbazide.

EXAMPLE 6 l-(3,5-diamino-o-chloropyrazinoyl)-3-butyl-4- phenyl-3 -thioisosemicarbazide By replacing the thiosemicarbazide and the methyl iodide employed in Example 1 by equimolecular quantities of 1-(3,5-diamino-6-chloropyrazinoyl)-4-phenylthiosemicarbazide (C6) and butyl bromide respectively, and then following substantially the same procedure described in Example 1, there is obtained 1-(3,5-diamino-6-chloropyrazinoyl -3-butyl-4-phenyl-3 -thioisosemicarbazide.

EXAMPLE 7 1-{3-amino-5-[2-(2-pyridyl)hydrazino] -6-chloropyrazinoyl}-3-benzyl-3-thioisosemicarbazide By replacing the thiosemicarbazide and the methyl iodide employed in Example 1, by equimolecular quantities of 1-{3-amino-5-[2-(2-pyridyl)hydrazino]-6-chloropyrazinoyl}-thiosemicarbazide, from preparation (C-7), and benzyl chloride and following substantially the same procedure described in Example 1, there is obtained 1- {3 amino-5-[2-(2 pyridyl)hydrazino]-6-chloropyrazin oyl}-3-benzyl-3-thioisosemicarbazide.

EXAMPLE 8 1-(3,S-diamino-G-chloropyrazinoyl)-3-(p-methylbenzyl) -4-methyl-3-thioisosemicarb azide By replacing the thiosemicarbazide and the methyl iodide employed in Example 1, by equimolecular quantities of 1-(3,S-diamino-6-chloropyrazinoyl)-4-methy1-thiosemicarbazide, from preparation (C-8), and p-methylbenzyl chloride respectively, and following substantially the same procedure described in Example 1, there is ob- EXAMPLE 1-{3amino-5-(2,2-pentamethylenehydrazino)-6-chloropyrazinoyl}-3 -phenethyl-3-thioisosemicarbazide By replacing the thiosemicarbazide and methyl iodide employed in Example 1, by equimolecular quantities of 1-[3-amino-5-(2,2-pentamethylenehydrazin0)-6 chloropyrazinoyl]-thiosemicarbazide, from preparation (C9),

rained 1 9qq v -(P- Y and phenethyl bromide respectively, and then following benlyl)'4'methyl'3'thlolsosemlcarbazldesubstantially the same procedure described in Example 1, there is obtained 1-[3-arnino-5(2,2-pentamethylene- EMMPLE 9 hydrazino)-6-chloropyrazinoyl] 3-phenethy1-3 thioiso- 1-(3,5-diamino-G-chloropyrazinoyl)-3-(p-chlorobenzyl)- semicarbazide.

4-methyl-3-thioisosemicarbazide Additional 1 (3 aminopyrazinoyl)-3-substituted-3- thioisosemicarbazide products prepared by the procedures By replacing the thiosemicarbazide and the methyl described in Examples 1 through 10 are identified in iodide employed in Example 1, by an equimolecular Table IV. The products are prepared by reacting the quantity of 1-(3,S-diamino-6-chloropyrazinoyl)-4-methyl- (3-aminopyrazinoyl)thiosemicarbazide (H) with the althiosemicarbazide, from preparation (0-8), and pkylating agent (III) to give the desired product I wherechlorobenzyl chloride respectively, and following subin X, Y, R and R have the significance given in the stantially the same procedure described in Example 1, table.

TABLE IV xj NH: S Y ooNHNE-Ji-NHm II III I Thiosemicarbazide from Prepn. X Y R R Exam 1e 11?. 0-10 01 'CH2CH=CH1 CH NHNH- N (02H5)2N Cl CH2CH=CH2 CH CH NH- Cl -0H2CH=CH2 -CH C2H5NH- C1 3 CH n-C3H NH- 01 0aH -n 03H1-n CH2=CHOH2NH Cl CH2CH=0H2 -CH 11-04HgNH- 01 -04H9-11 C Ha-n C5 01 0 H7-I1 -C3H7-D CHNH- 19 0-19 (CHa)a0NH 01 0HOIE[=OH -CH 20 0-20 01 -0m0H=CHz 0HzOgH 21 0-11 H 01 -0H20H5 -(CH2)2C5H5 22 0-22 0H OCHzCH2NH 01 CHzCH=0Hz OH C H 23 0-23 01 0H2CH=CH -C H Cl CH2NH 24 0-24 0 01 -0H20H=CH2 -0H -0H2NH N 25 0-25 01 CHzCH=CH CH;;

1 CHzNH- N 2 0-26 E 01 0 H n C 11- 6 N/ cHmH- 4 r 4 o 27 0-27 I? 01 C4Hrn -G H -n CHNH(0H2)2NH 28 0-21 H I H TABLE IVContinued Thiosemicarbazide from Prepn. X Y R1 R Example 54 -54 NH- 01 C H -n -CHzC H 55 0-55 onzoonmn- 01 OH2CH=CH2 CH2 5:; O-66 'CH2NH 01 H CH2-C5H5 51 o- /N CH3 -0H5 -OH o11,

58 C-58 CFsCHzNH- Cl -H2CC8H5 -CH3 59 0-59 OF CHzCHzNH- 01 -CH2CH=OH2 0 11 -5 50 0450 OH3-OHzNH 01 CHzOH=CH2 -C H -n s1 0 51 HzCHzNH o1 'H2C'-C6H5 0Hz-C1 O 62 0 52 W Tcamn- 01 -CH2OH=CH -0H.

53 0453 02H5N(C.Hz)zNH- 01 -OHzCH=CH -CH3 54 o-64 N: (CIEIz)2NH-- c1 -CHzCH=CH -om 05 (Hi5 N-(OHMNH- O1 CH2CH=OH2 CH;;

55 0-57 (HQ-NEH 01 -(CH2)2C5H5 0H. 2-0.,11

The preparation of the novel (3 amino-5-X-6-Y- pyrazinoyl)-thiosemicarbazides by the second method, i.e., through the acrylamides, is described in the following preparation and examples.

PREPARATION OF PYRAZINOIC ACIDS (D-l) Preparation of 3,S-diamino-G-chloropyrazinoic acid A mixture of finely ground methyl 3,5-diamino-6- chloropyrazinoate (101.31 g.; 0.50 mole), isopropyl alcohol (1875 ml.) and 5% aqueous sodium hydroxide solution (625 ml.) is heated under reflux, with vigorous stirring, for one hour. Water (7500 ml.) is added to the cooled reaction mixture and the resulting clear solution is made acid to Congo red paper by the addition of concentrated hydrochloric acid. The light yellow solid which separates is collected and dried, yield 92.8 g. (94.4%), M.P. 230-1 C. (dec.). Recrystallization from dimethyl sulfoxide-water gives 3,5-diamino 6 chloropyrazinoic acid, M.P. 272 C. dec.

Analysis.-Calculated for C H Cl'N O (percent): C, 31.84; H, 2.67; N, 29.71. Found (percent): C, 32.10; H, 2.65; N, 29.57.

(D-2) Preparation of 3-amino-5- (2-propynylamino 6-chloropyrazinoic acid Utilizing the procedure substantially as described in preparation (D-l), but substituting for the methyl 3,5- diamino-6-chloropyrazinoate employed therein, an equimolar amount of methyl 3-amino-5-(2-propynylamino)-6- chloropyrazinoate, from preparation (A-4), there is produced 3-amino-5-(2-propynylamino) 6-chloropyrazinoic acid.

(D-3) Preparation of 3-amino-5-ethylamino-6- chloropyrazinoic acid A mixture of methyl 3-amino-S-ethylamino-G-chloropyrazinoate (20.0 g.; 0.087 mole) and 5% aqueous sodium hydroxide solution (200 m1.) is heated on a steam bath for two and one-half hours. The resulting solution is acidified with 6 N hydrochloric acid (35 ml.) The light tan colored solid which separates is collected and dried, yielding 15.0 g. of 3 amino 5 ethylamino-6- chloropyrazinoic acid, M.P. ISO-154 C. (dec.).

(D-4) Preparation of 3-amino-5-dimethylamino-6- chloropyrazinoic acid A mixture of methyl 3-amino 5 dimethylamino-6-' (D-5 Preparation of 3-amino-5-(2-dimethylamino ethylamino) -6-chloropyrazinoic acid A solution of methyl 3-amino-5 (Z-dimethylaminoethylamino)-6-chloropyrazinote (2.74 g.; 0.01 mole) and potassium hydroxide (1.20 g.; 0.02 mole) in methanol (25 ml.) is refluxed for six hours and the methanol is removed under reduced pressure. The residue is dissolved in water (20 ml.) and neutralized by the addition of dilute hydrochloric acid. The solid that precipitates is collected and dried to give 2.42 g. of 3-amino-5-(2-dimethylaminoethylamino) 6-chloropyrazine acid, M.P. 217-219 C. (dec.).

AnaIysis.Calculated for C H ClN O (percent): C, 41.62; H, 5.43. Found (percent): C, 42.14; H, 5.62.

Employing the procedure substantially as described in preparation (D-l) but substituting for the methyl 3,5- diamino-6-chloropyrazinoate an equivalent amount of the methyl or other lower alkyl 3-amino-5-X-6-Y-pyrazinoate identified in the following table, there are produced the 3-amino-5-X-6-Y pyrazinoic acids, also identified in Table V.

TABLE v N N X NHZ X- \NH2 J Y\\\N/COOCH3 Y\\N COOH Preparation:

D-fi H2N I D-7 H2N Br D-S orn-NH- c1 D-9 CHz=CHCHz-NH c1 1 -1o NH c1 D-ll CHz-NH or -12 no CHfiHQ-NH- or 15-13 HO CH2(OHOH) CHzNH* or 15-14 ORCHz-NH- or 15-15 cmm1 01 l D-l6 CH2NH- or i I CHz-NH 01 D-18 NI 01 13-19 o1-Qm1- c1 15-20 CHgO-(CHQ-N- or 15-21 NHg-(CH )N or 13-22 N- or Derived from D-glucamine.

PREPARATION OF THE 3-(3-AMINO-5-X-6-Y- PYRAZINOYL)ACRYLAMIDES (E-l) Preparation of N-(t-butyl)-3-methyl-3-(3,5- diamino-6-chloropyrazinoyloxy)acrylamide A mixture of 3,5-diamino-6-chloropyrazinoic acid (1.80 g.; 0.01 mole), from preparation (D 1), and triethylamine (1.0 g.; 0.01 mole) in dimethylformamide (20 ml.) is stirred for ten minutes. N-(t-butyl)-methylisoxazoli um perchlorate (2.40 g.; 0.01 mole) is added and the resulting solution stirred two hours. Water (100 ml.) is added and the solid that separates is collected and dried to give 2.85 g. (87%) of N-(t-butyl)-3-methyl-3-(3,5-diamino- 6-chloropyrazinoyloxy)acrylamide, M.P. 171176 C. Recrystallization from acetonitrile gives the product in the form of light yellow crystals, M.P. 187189 C.

28 Analysis.-Calculated for C H ClN O (percent): C, 47.63; H, 5.53; N, 21.37. Found (percent): C, 47.87; H, 5.55; N, 21.42.

(E2) Preparation of N-(t-butyl)-3-methyl-3(3-amino- 5-ethylamino-6-chloropyrazinecarbonyloxy) acrylamide A mixture of 3-amino 5 ethylamino 6 chloropyrazinoic acid (2.17 g.; 0.01 mole), from preparation (D3), and triethylamine (1.0 g.; 0.01 mole) in dimethylformamide (20 ml.) is stirred for ten minutes. N-(tbutyl)-5-methylisoxazolium perchlorate (2.40 g.; 0.01 mole) is added and the resulting solution is stirred for three hours. Water (100 ml.) is added and the solid which separates is collected and dried, yield 2.9 g. of N-(t-butyl) 3 methyl-3-(3-amino-5-ethylamino-6- chloropyrazinecarbonyloxy)acrylamide, M.P. 136140 C.

(E-3) Preparation of N-(t-butyl) 3 methyl 3 (3- amino 5 dimethylamino-6-chloropyrazinecarbonyloxy(acrylamide A mixture of 3-amino 5 dimethylamino 6 chloropyrazinoic acid (2.2 g.; 0.01 mole), from preparation (D-4), and triethylamine (1.0 g.; 0.01 mole) in acetonitrile (60 ml.) is stirred for ten minutes. N-(t-butyl-S- methylisoazolium perchlorate (2.4 g.; 0.01 mole) is added and the resulting mixture is stirred for three hours. The acetonitrile is evaporated under reduced pressure, the residue washed with several portions of water and dried, yield 3.5 g. (98%) of N-(t-butyl) 3 methyl-3- (3-amino 5 dimethylamino-6-chloropyrazinecarbonyloxy)acrylamide, M.P. 150-153 C. (dec.). Recrystallization from butyl chloride gives material melting at 154-l55 C. (dec.).

Analysis-Calculated for C H ClN O (percent): C, 50.63; H, 6.23; N, 19.68. Found (percent): C, 50.37; H, 6.25; N, 19.70.

(E-4) Preparation of N-(t-butyl) 3 methyl 3 [3- amino 5 (2 dimethylaminoethylamino)-6-chloropyrazinoyloxy] acrylarnide 3-amino 5 (2 dimethylaminoethylamino) -6-chloropyrazinoic acid (2.60 g.; 0.01 mole), from preparation (D-5), and triethylamine (7.5 ml.) are mixed in dimethylformarnidc (75 ml.). N-(t-butyl)-5-methylisoxazolium perchlorate (2.40 g.; 0.01 mole) is added and the solution is stirred for three hours. The reaction mixture is diluted with Water 75 ml.) and the aqueous solution is extracted three times with ethyl acetate (75 ml.). The ethyl acetate extracts are dried over anhydrous magnesium sulfate and then evaporated under reduced pressure. The residue is diluted with water (100 ml.) and the solid that forms is collected and dried at 60 C., yield 1.27 g. of N (t butyl) 3 methyl 3 [3- amino-S-(Z-dimethylaminoethylamino) 6 chloropyrazinoyloxy]acrylamide, M.P. 130 C. Recrystallization from acetonitrile gives material with M.P. -133 C. Drying of this material at 80 C. under vacuum gives material with M.P. 153155 C.

Analysis.-Calculated for C H C1N O (percent): C, 51.18; H, 6.82; N, 21.07. Found (percent): C, 51.01; H, 6.76; N, 20.86.

(E-S) Preparation of N(t-butyl)-3-methyl-3-(3-amino- 6-chloropyrazinoyloxy)acrylamide A mixture of 3-amino-6-chloropyrazinoic acid (9.2 g.; 0.0526 mole), triethylamine (7.4 ml.) and acetonitrile (100 ml.) is stirred until complete solution is obtained. N-(t-butyl)-5-methylisoxazolium perchlorate (12.6 g.; 0.0526 mole) is added and the solution is stirred at room temperature for two hours. Water (500 m1.) is added and the solid that separates is collected and recrystallized from butyl chloride to give 12.2 g. of N-(t-butyl)-3- methyl-3-(3-amino 6 chloropyrazinoyloxy)acrylamide, M.P. 144146 C.

(15-6) Preparation of N-(t-butyl)-3-methyI-3-(3-aminopyra zinoyloxy) acrylamide S-aminopyrazinoic acid (6.95 g.; 0.05 mole) is mixed with acetonitrile (100 ml.) and dissolved by the addition of triethylamine (7.0 ml.; 0.05 mole). N-(t-butyl)-5- methylisoxazolium perchlorate (12.0 g.; 0.05 mole) is added and the solution is stirred at room temperature for 10 four hours; The solvent is removed under reduced pressure and water (50 ml.) is added to the residue. The

X NHz R3 Y \N OOOH H solid that separates is collected and dried to give 11.45 g. of N-(t-butyl) 3 methyl-3-(3-aminopyrazinoyloxy) acrylamide, M.P. 113-120 C. Recrystallization from methylcyclohexane gives material with M.P. 122126 C.

Employing the procedure substantially as described in preparation (E-l) but substituting for the 3,5-diamino- 6-chloropyrazinoic acid and the N-(t-butyl) methylisoxazolium perchlorate utilized therein, equivalent amounts of 3-amino-5-X-6-Y-pyrazinoic acid and N-R 5-R -4-R -isoxaz01ium salt respectively which are identified in Table VI, there are produced the N-R -2-R -3-'R 3 (3 amino-S-X-6-Y-pyrazinoyloxy) acrylamides, also identified in Table VI.

TABLE VI Acid frrom [9 aratign X Y R R3 R4 Z Preparation: 6

12-7 13-2 HC O-OHr-NH- 01 cup I n (cH nc- 010, 12-8 D-6 H2N- I msQ H omen.- no 19-7 HzN- Br Q- E wmho- 010.

E- D-8 OHaNH- 01 CH3- :1 cnmoe10 1P0: E-ll n-a CH2=(JHCH2NH- o1 -CH=0H-OH=CH- 0H.- oar-@40 E-12 13-10 N-NH- e1 0118-- H onmoe10.

E-13 n-11 GHz-NH- c1 ms-Q H 0113032- 12-14 13-12 HOGHaCHz-NH- 01 OH3- n omno- 010.

12-15 12-13 H0CH2(CHOH)4OH2NH 01 -CH=CHCH=CH- CH3- QNQ-sm N02 E-16 19-14 OF3OH2NH- 01 Q- (0m .o 01o. E-17 D- -011Hsn- 01 OH.- H (onmo- 010,

l I 13-18 D-16 Q-cm-nnc1 ms-Q H entom- 0 9 E49 13-17 W WCH2NH 01 on? H cnmo- 01o.

E-20 n48 -NH- 01 cm- H (011.)- 010.. E-21 D-19 ClQ-NE- o1 OH=CH--CH=OH- cmomQ-so N02 E-22 15-20 omo(cH.)-N 01 Q- E (011.)..0- 1:10..

15-23 13-21 NHr-(CHQ-N- 01 on.- H oname10.

n-zq. 13-22 N 01 cm- H onmoc10 n The anion appears as part of the R substitnent; the product appears as the triethyl ammonium salt. b This compound is not strictly an acrylamide but rather N-R -2-(3-amino-5-NR R"-6-halopyrazinoyloxy)benzamlde;

I50 LENA! 5 m 26 mo m o mo mo mo 6 mz mo mo io m R NOZ Lm Q O S .5255 2 w 5 8 m m mo 6 mz mo 07m 3 6Q I o qmov m O 5 25 m m .355 mm 25% A QV 3 mo mo m 3 w o H 2 m I50 50 18-..-.. ....46..:. 1 3% 5 M w mh Q QLO 8 8 m 18:.) m m EH fl 6Q imo w 6 m ow HO m m mm 5 m i 2 3% 5 iz ioio zx mov Tm 525a ,2 w 2 QA QV it-.. 2:5 3 25m 525 3 25m m 32 W 22 5 1 23 l JHU llnmo @XZO Ofi mov m (WHO #0 mzmmno NIH ww 6353a m m 5 Q a Q N :58

@A 5 5 N N 532% mm mm -NHAZT O Z QZOO "30.55 83.3 2 05 b zomtmm 23 H0 933 -Eu 22: 5 5 003 253a 05 9 moucois v5 wc E: 2. 3238 on 2 on EN EN $25253 05 Bo c2302: 5 0 mucnomEoo 2 w xmE how 26508 05 we 03 .53: 98 338m m Bo 2 596m m low low-llnmn mO -O IIZ wu m -oo /l.l| [:6 A OV 135m m m 50 6 Z mo mZ ME" mm 4 58% Q 6 omov m O 6 z mo o mo NEH 6 3 52 LMQIQ Q Q m mo mo mo mo 6 ETQ B a m a m 6 .LHHO IMmO OR NOV m HO HO MZ EOE 2 m mw LMOIQ O 3 Lmonmo m OwS 6 NZ EO O fi m r m 35m 35 m 6 6 MZ EO O fi m mw E6 8 56 omov m Q 6 mZ mo mo 2 m 6 "0% Q :wnam Qm O ZS mo A mo mo mo mo 6 mz fioxmomov moom fi m s 58% O ox mov m mo 6 mz fio moom 3 m IEOIA V A U 3 Lmommo M O QO 6 MZ mU A fi m IEOIQ IQIHO 2366 m mo 6 mz fi m uofifian m m .N m "N NM W um .635 dmm m as. 025 63.64

The novel compounds of this invention can be formulated in the usual oral or parenteral dosage forms for use in therapy in the treatment of conditions resulting from an abnormal electrolyte excretion pattern of an animal organism. It will be appreciated that the dosage of each individual compound will vary over a wide range depending upon the relative potency of the selected compound and also depending upon the age and weight of the particular patient to be treated and upon the particular ailment to be treated. For these reasons, tablets, pills, capsules and the like containing for example from to 500 mgs. or more or less active ingredient can be made available for the symptomatic adjustment of the dosage to the individual patient. As each of the compounds of this invention can be incorporated in a dosage form similar to those described in the following examples, or other usual dosage forms suitable for oral or parenteral administration, which can be prepared by well-known methods, the following examples are included herein to illustrate the preparation of representative dosage forms.

EXAMPLE 91 Dry filled capsule containing 500 mgs. of l-(3,S-diamino-6-chloropyrazinoyl)- 3-methyl-3-thioisosemicarbazide mgs./capsule Active ingredient 500 Magnesium stearate 5 Mixed powders 505 Mix the active ingredient with the magnesium stcarate and reduce to a No. 60 mesh powder. Encapsulate, filling 505 mgs. in each number 0 capsule.

It is also contemplated to combine compounds of this invention in unit dosage form with other known diuretic agents, such as hydrochlorothiazide, 4-methyl-6-chlorospiro [ZH-l,2,4-benzothiadiazine-l-cyclohexane] 7- sulfonamide-l,l-dioxide, trichloromethiazide, cyclopenthiazide, acetazolamide, dichlorophenamide, chlorthalidone, chlormerodrin, chlorazanil, spironolacetone, and the like or to combine the compounds of this invention with hypotensive agents or steroids or other desired therapeutic agents in suitable dosage form.

While the above examples describe the preparation of certain compounds which are illustrative of the novel compounds of this invention and certain specific dosage forms suitable for administering the novel compounds, as well as certin methods for preparing the novel compounds, it is to be understood that the invention is not to be limited to the specific compounds described in the Examples or by the specific reaction conditions provided in the Examples for their preparation or by the specific ingredients included in the pharmaceutical preparations, but is to be understood to embrace variation and modification thereof which fall within the scope of the appended claims.

What is claimed is:

1. A proces for the preparation of a 1-(3-aminopyrazinol)-3-substituted-3 thioisosemicarbazide having the structure:

(ll) (Ill) wherein in each of the foregoing structures X is selected from hydrogen and an amino having the structure NR R wherein R is selected from (1) hydrogen, (2) lower alkyl and (3) lower alkenyl; R is selected from (1) hydrogen, (2) lower alkenyl, (3) lower alkynyl, (4) C cycloalkyl, (5) phenyl and substituted phenyl, wherein the substituent(s) are selected from halogen, lower alkyl and lower alkoxy, (6) lower alkoxy, (7) pyridylamino and pentamethyleneamino, (8) lower alkyl and substituted lower alkyl wherein the substituent(s) are selected from (a) lower alkoxy,

(b) C cycloalkyl,

( py y (e) phenyl and substituted phenyl wherein the substituent(s) are selected from halogen, lower alkyl and lower alkoxy,

(f) -NR"R wherein R is selected from (i) lower alkyl and (ii) lower alkylcanbonyl, R is lower alkyl and R and R taken together with the nitrogen to which they are attached form a 5 or 6 membered ring selected from piperidino, pyrrolidinyl, morpholing, piperazinyl, N-lower alkyl piperazinyl, an R and R taken together with the nitrogen to which they are attached form a 5 to 6 membered ring selected from piperidino, pyrrolidinyl, morpholino, piperazinyl and N-lower alkyl piperazinyl;

Y is selected from hydrogen, lower alkyl, halogen and phenyl; R is selected from lower alkyl, phenyl-lower alkyl, lower alkyl-phenyl-lower alkyl and halophenyl-lower alkyl; R is selected from hydrogen, lower alkyl, lower alkenyl, phenyl, halophenyl, phenyl-lower alkyl and diphenyl-lower alkyl.

2. A process as claimed in claim 1 wherein the reaction is carried out in the presence of a solvent.

3. A process for the preparation of 1-(3,5-diamino-6- chloropyrazinoyl)-3-methyl 3-thioisosemicarbazide comprlslng the reaction of l-(3,S-diamino-6-chloropyrazinoyl)-thiosemicarbazide and a methyl halide in a lower alkanol in the presence of a base.

4. A process for the preparation of l-(3-aminopyrazinoyl)-3-substituted-thioisosemicarbazide having the structure s R Y \N CONHN -C-NHR characterized in that an acrylamide of structure VI is caused to react with a 3-substituted-3-thioisosemicarbazide of structure VII 1) (Vll) wherein in each of the foregoing structures X, Y, R and R have the meaning assigned in claim 1, R is selected from lower alkyl, phenyl, lower alkyl-substituted phenyl and phenyl substituted with a sulfonate anion; R is selected from hydrogen and a hydrocarbon radical which when linked to R forms with the carbon atoms to which R and R are joined an ortho-phenylene group; and R is lower alkyl.

5. A process as claimed in claim 4 wherein the reaction 5 is carried out in the presence of a solvent and with heating.

6. A process as claimed in claim 5 wherein N-(lower alkyl)-3-(3,5 diamino-6-chloropyrazinoyloxy) acryla- 10 mide and 3-methyl-3-thioisosemicarbazide are caused to react to form 1-(3,S-diamino-6-chloropyrazinoyl)-3-methyl-3-thioisosemicarbazide.

7. A compound having the structure XININHZ SIR 1 Y \N ooNHN C NHR and pharmacologically acceptable salts thereof wherein X is selected from hydrogen and an amino having the structure -NR R wherein R is selected from (1) hydrogen, (2) lower alkyl and (3) lower a1kenyl;

R is selected from 1 hydrogen,

(2) lower alkenyl,

(3) lower alkynyl,

(4) 03-7 cycloalkyl,

(5) phenyl and substituted phenyl, wherein the substituent(s) are selected from halogen, lower alkyl and lower alkoxy,

(6) lower alkoxy,

(7) pyridylamino and pentamethyleneamino,

(8) lower alkyl and substituted lower alkyl wherein the substituent(s) are selected from (a) lower alkoxy,

(b) C3-6 cycloalkyl,

( py v (e) phenyl and substituted phenyl wherein the substituent(s) are selected from halogen, lower alkyl and lower alkoxy,

(f) --NR' R wherein R is selected from (i) lower alkyl and (ii) lower alkylcarbonyl, R is lower alkyl and R" and R taken together with the nitrogen to which they are attached form a 5 or 6 membered ring selected from piperidino, pyrrolidinyl, morpholino, piperazinyl, N-lower alkyl piperazinyl, and R and R taken together with the nitrogen to which they are attached form a 5 to 6 membered ring selected from piperidino, pyrrolidinyl, morpholino, piperazinyl and N-lower alkyl piperazinyl;

Y is selected from hydrogen, lower alkyl, halogen and phenyl; R is selected from lower alkyl, phenyl-lower alkyl, lc wer alkyl-phenyl-lower alkyl and halophenyl-lower alkyl; R is selected from hydrogen, lower alkyl, lower alkenyl phenyl, halophenyl, phenyl-lower alkyl and diphenyl-lower alkyl.

-8. A compound as claimed in claim 7 wherein X is amino, R is lower alkyl and R is hydrogen.

9. A compound as claimed in claim 7 wherein X is amino, Y is chloro, R is methyl and R is hydrogen.

10. A compound as claimed in claim 7 wherein X is amino, Y is chloro, R is methyl and R is allyl.

References Cited UNITED STATES PATENTS 3,444,165 5/1969 Pollack et a1 260-450 3,472,848 10/ 1969 Cragoe et a1 260250 NICHOLAS S. RIZZO, Primary Examiner US. Cl. X.R.

3,555,023 Dated January 12, 1971 Patent No.

Inventor) Edward J. Cragoe, Jr. and Kenneth L. Shepard It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

r- In column 4, line 45, correct structure XII to appear as follows:

In Table II, Preparation B-33, the "M.P. C. column change "13-46" to read -l34-6-; and Preparation B-55, in the "Y" column, change "DH to read ---CH In Column 13, line 70 change the empirical formul to read --C H ClN OS--. In column 14, Tina 122 change melt point to rea 20 208.5 C.--; and in line 73, change "5. 8 g. to read ---5. 89 g.. In Table III, in Preparation C-25, in the structure in the "X" column, change "CHNH to read ---CH NH---. In Table IV, Example 11, in the structure in the "X" column, change the ring to read as follows:

If in Example 32, change the structure in the "X" column to read (CH N(CH NH- In Table VI, Pr aration E-lO in t1 column, change "Cl to read -Cl0 in Preparation E-l2, correct the structure in the "X" column to read as follows:

in Preparation E-l3, correct the structure in the "R column 1' read as follows: 

